Tableview不会reloadData（）

Question

Sup guys? Need some help over here. I used the delegate protocol to pass some strings back from a "second view controller" to it's previous one.

My array appends the string from the method I implemented on the delegate protocol, but everytime I press "add" and come back to the first screen, the table view doesn't change. I'm not sure if the string is not being passed between views or if it's just the table view that isn't reloading.

The code is quite simple:

import UIKit

class EsseVaiReceber: UIViewController, UITableViewDataSource, UITableViewDelegate, PassInfoDelegate   {

    @IBOutlet var listaDeCoisasAFazer: UITableView!
    var arrayInfo : [String] = []
    var stringReceived: String = ""

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        listaDeCoisasAFazer.reloadData()
        print("SCREEN APPEARED")

    }

    override func viewDidLoad() {
        super.viewDidLoad()
        listaDeCoisasAFazer.reloadData()
        print("LOADED SCREEN")
    }

    func passInfo(infothatwillpass: String) {
        arrayInfo.append(infothatwillpass)
    }


    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return arrayInfo.count
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as UITableViewCell!
        let row = indexPath.row
        let titulo = arrayInfo[row]
        cell.textLabel!.text = titulo

        return cell
    }

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if(segue.identifier == "add") {
            let view = segue.destinationViewController as! EsseVaiPassar
                view.delegate = self
        }
    }

}

and :

import Foundation
import UIKit

protocol PassInfoDelegate {
    func passInfo(infothatwillpass: String)

}

class EsseVaiPassar: UIViewController {

    @IBOutlet var campoTitulo: UITextField!
    var delegate: PassInfoDelegate?
    var textinput: String = ""


    @IBAction func botaoAdicionarCoisasAFazer(sender: AnyObject) {

        if campoTitulo == nil { return }
        textinput = campoTitulo!.text!
        print("TEXTO NO CAMPO:\(textinput)")

        if delegate == nil {
            print("DELEGATE IS NILL")
            return
    }

        delegate!.passInfo(textinput)
        print("TEXTO DO DELEGATE: \(textinput)")

        if let navigation = self.navigationController {
            navigation.popViewControllerAnimated(true)
            print("INFO QUE VAI PASSAR: \(textinput)")
        }
    }
}

Any ideas why the table view won't populate? Thanks advanced =)

Answer 1

The tableView is using arrayInfo as the source for the listaDeCoisasAFazer tableView data (indirectly). If you change arrayInfo you need to tell listaDeCoisasAFazer to reloadData() .

func passInfo(infothatwillpass: String) {
    arrayInfo.append(infothatwillpass)
}

You can/should remove the reloadData() from viewWillLoad and viewDidLoad as the dataSource hasn't changed so there is no need to reload the data.

TIP

You are checking for nil before the delegate call in the destination viewController. Unless you are doing this for debugging purposes, you can simply call delegate?.passInfo(textinput) . If delegate is nil, it will just ignore the call.